Cutter-head for boiler-tube cleaners



P. J. DARUNGTON.

CUTTER HEAD FOR BOILER TUBE CLEANERS.

APPLICATION FILED APR.30, 1919.

1,3682%; Patented. Dec. 28; 1920.

3 SHEETS-SHEET I.

A 7 far/72g P. J. DARLINGTON.

CUTTER HEAD FOR BOILER TUBE CLEANERS- APPLICATION FILED APR.30, 1919.

1 063,232. Patfited Dec. 28 1920.

3 SHEETS-SHEET 2- P. J. DARLINGTON.

CUTTER HEAD FOR BOILER TUBECLEANERS.

APPLICATION FILED APR. so, 1919.

1,,fi3 232. Patented Dec. 28, 1920.

3 SHEETS-SHEET 3- UNITED stares PATENT QFFICE.

PHILIP .r. DARLINGTON, or HARTFORD, CONNECTICUT, nssrGNon To THE ROTO COMPANY, or HARTFORD, CONNECTICUT, A CORPORATION or CONNECTICUT.

CUTTER-HEAD FOB BOILER-TUBE CLEANERS.

Specification of Letters Patent.

Patented Dec. 28, 1920.

Application filed April 30, 1919. Serial No. 293,592.

T 0 all whom it may concern:

Be it known that I, PHILIP J. DAR I C- TON, a citizen of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented a new and useful Improvement in Cutter-Heads for Boiler-Tube Cleaners, of which the following is a specification.

This invention relates to the type of cutter heads for cleaning the deposit from the interior of boiler tubes, which have cutters mounted on the ends of arms that at their other ends are connected with a body frame by transversely-extending pivots in such manner that the arms normally lie close to and extend parallel with the axis of rotation and the cutters oscillate radially under centrifugal action when rotated.

The object of the invention is to construct a head of this nature with a number of strong, durable cutters, so arranged that they will nest together and normally lie compactly close to the axis of rotation and will be capable of extended outward movement, thereby rendering the head adaptable for use in tubes of widely differing diameters, as well as in tubes that are very much choked with deposit, the said cutters being so shaped in contour that the cutting edges of the teeth remain tangent to the wall of the boiler tubes throughout the entire range of variation of angle of both the long arms and the short arms as they swing on their transverse pivots, thus eliminating the danger of cutting, or gouging, or scratching the inner surfaces of the tubes.

This Object is attained by mounting two cutters on the ends of relatively long arms that are cross-pivoted at their other ends to diametrically opposite sides of the body frame, and mounting two cutters on the ends of somewhat shorter arms that are cross pivoted to the frame at their other ends diametrically opposite each other between the long arms, so that the pairs of arms swing outwardly in planes at right angles to each other, the pivots for the arms being in the same locality the cutters on the short arms close in back of the cutters on the long arms, and the contour of the cutter teeth on the short arms being curved on different radii from the teeth on the long arms so as to compensate for differences in the length of and the changes of angular F igure 1 of the accompanying drawings shows a plan of a cutter head constructed according to this invention. Fig. 2 is a View looking at the rear end of the head. Fig. 3 1s a view looking at thecutter end of the head. Fig. 4. is a perspective view of the-body frame to which the cutter arms are plvoted. Fig. 5 is a horizontal section through a long cutter arm and the cutter carried thereby. Fig. 6 is a horizontal section through a short cutter arm and cutter.

The body frame 1 which is shown has a central, rearwardly projecting, and preferably integral, threaded hub 2 for attachment to the driving means, and is provided with longitudinally-extending grooves 3 that Open outwardly on four sides. In order to obtain as great a depth as possible for the grooves with a minimum weakening of the frame, the corners 4. at the bottoms of the grooves are beveled.

The cutter carrying arms are similar except as to length, the arms 5 being somewhat shorter than the arms 6. These arms are shaped to fit and oscillate in the grooves 1n the sides of the frame, the short arms 5 being arranged opposite each other and held by short transversely extending pivot pins 7 and the long arms 6 being arranged oppo site each other and held by long transversely extendlng pivot pins 8 which have split ends. When the arms are located in the grooves, the short pivots are driven in and then the long pivots are driven in and their ends spread so as to retain them in place, and as the long pivots project opposite the ends of the short pivots they also hold the short pivots in place.

The cutters 9 are loosely mounted on headed screw studs 10 that are screwed into the free ends of the short arms, and the cutters 11 are loosely mounted on headed screw studs 12 that are screwed into the free ends of the long arms, the arms being of such length that when folded in, the opposite cutters will come together with the cutters on the short arms nesting back of the cutters on the long arms. T he screw studs may turn into the arms and butt against the pivot pins. By reason of this arrangement, four strong, durable cutters may be provided and these cutters while having a wide range of swing, closely compact so that the head may be used in a small tube or where the initial opening of a tube is very small owing to deposit.

The cutters are crown or acorn shape, and the teeth extend in radial planes with their cutting edges curved on arcs of circles of such radii that from their inner positions to the extreme outward limits of their throw the active edges of the teeth will always be tangent to the longitudinal line of the wall of the tube being cleaned. In order that this condition may result, as the cutters on the short arms oscillate on a shorter radius than the cutters on the long arms the contour of the teeth on the cutters of the short arms will be arcs of shorter radii than the radii of the arcs of the teeth of the cutters on the long arms.

This invention provides a strong, durable, compact cutter head that is capable of cleaning small tubes and has a wide radius of action without danger of injuring the tubes being cleaned.

The invention claimed is:

1. A cutter for a tube cleaner having a body with longitudinallyextending out wardly-opening grooves in its sides, long arms held at one end by transverse pivots in opposite grooves, cutters rotarily mounted on the free ends of said long arms, short arms held at one end by transverse pivots in opposite grooves, cutters rotarily mounted on the free ends of said short arms, the cutters on the short arms, when the arms are closed, lying close back of the cutters on the long arms, with the cutting teeth of the cutters on the short arms curved longitudinally on arcs of shorter radii than the cutting teeth of the cutters on the long.

arms.

2. A cutter for a tube cleaner having a body with longitudinally-extending outwardly-opening grooves in its sides, long arms held at one end by transverse pivots in opposite grooves, cutters rotarily mounted on the free ends of said long arms, short arms held at one end by transverse pivots in opposite grooves, cutters rotarily mounted on the free ends of said short arms, the cutters on the short arms having cutting teeth that are shorter than the cutting teeth of the cutters on the long arms and that are curved longitudinally on arcs of shorter radii than the cutting teeth of the cutters on the long arms.

3. A cutter for a tube cleaner having a body, arms of different lengths hinged to the body, and cutters having cutting teeth curved longitudinally of the axes of the cutters, rotarily'mounted on the swinging ends of said arms, the arcs of the edges of the cutting teeth of the cutters on the shorter arms being formed on shorter radii than the radii of the arcs of the edges of the cutting teeth of the cutters on the longer arms.

4:. A cutter for a tube cleaner having a body with a plural number of longitudinal grooves opening outwardly from opposite sides, arms held at one end by transverse pivots in opposite grooves, arms held at one end by transverse pivots in opposite grooves, said pivots being in the same transverse plane and the pivots of one set of arms projecting in front of and preventing the piv-- ots of the other set of arms from working out of the body, headed studs screwed into the free ends of the arms and impinging against the pivots thereof, and cutters loosely mounted on the studs.

PHILIP J. DARLINGTON. 

